 /*******************************************************************************
  * Copyright (c) 2006, 2007 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/

 package org.eclipse.core.databinding.observable.map;

 import java.util.Set ;

 /**
  * @since 1.1
  *
  */
 public abstract class MapDiff {

     /**
      * @return the set of keys which were added
      */
     public abstract Set getAddedKeys();

     /**
      * @return the set of keys which were removed
      */
     public abstract Set getRemovedKeys();

     /**
      * @return the set of keys for which the value has changed
      */
     public abstract Set getChangedKeys();

     /**
      * Returns the old value for the given key, which must be an element of
      * {@link #getRemovedKeys()} or {@link #getChangedKeys()}.
      *
      * @param key
      * @return the old value for the given key.
      */
     public abstract Object getOldValue(Object key);

     /**
      * Returns the new value for the given key, which must be an element of
      * {@link #getChangedKeys()} or {@link #getAddedKeys()}.
      *
      * @param key
      * @return the new value for the given key.
      */
     public abstract Object getNewValue(Object key);
 }

